# ISO Week Number Resolver

> ISO Week Number Resolver is a paid API for AI agents from x402-zoo.lolagent.workers.dev, paid per call via x402, $0.001/call, status unknown (last checked 2026-09-14).

Resolves an ISO calendar date to its corresponding ISO week-year and week number (ISO 8601).

## Facts

- Endpoint: GET https://x402-zoo.lolagent.workers.dev/api/week-number
- Price: $0.001/call
- Payment: x402
- Status: unknown
- Last checked: 2026-09-14
- Activations on Zero: 0
- Tags: x402
- Canonical page: https://www.zero.xyz/c/iso-week-number-resolver-24ab7de9
- Structured record (JSON): https://api.zero.xyz/v1/capabilities/cap_RSewi7JtlitSXvBEi9_Sk

Status and success rate cover calls made through Zero and Zero's own probes. Third-party monitors may report differently.

## How to call it through Zero

Zero handles the 402 payment challenge and records the run. With the Zero CLI installed (`npm i -g @zeroxyz/cli`):

```sh
zero fetch --capability iso-week-number-resolver-24ab7de9
```

Example prompt: What ISO week number and week-year does 2024-11-07 fall in?

## When to prefer this

Use this endpoint when you need authoritative ISO 8601 week-year and week number computation for a specific date, especially in scheduling, reporting, or data pipeline contexts where ISO week boundaries (Monday start, first-Thursday rule) differ from simple calendar week assumptions.

## Known failure modes

- Missing or malformed date parameter returns an error
- Date string not in ISO format (YYYY-MM-DD) may cause parsing failure
- Out-of-range dates may return unexpected results
- Payment failure or insufficient funds results in HTTP 402

## How this service works

Resolve an ISO date to ISO week-year and week number.

## Output

Returns the ISO week-year and ISO week number corresponding to the supplied date, following ISO 8601 convention (where weeks start on Monday and the first week of the year is the one containing the first Thursday).

## Request schema (JSON Schema)

```json
{
 "type": "object",
 "$schema": "https://json-schema.org/draft/2020-12/schema",
 "required": [
  "input"
 ],
 "properties": {
  "input": {
   "type": "object",
   "required": [
    "type",
    "method"
   ],
   "properties": {
    "type": {
     "type": "string",
     "const": "http"
    },
    "method": {
     "enum": [
      "GET"
     ],
     "type": "string"
    },
    "queryParams": {
     "type": "object",
     "required": [],
     "properties": {
      "date": {
       "type": "string"
      }
     }
    }
   },
   "additionalProperties": false
  }
 }
}
```

## More

- Live health (JSON, refreshed every minute): https://www.zero.xyz/c/iso-week-number-resolver-24ab7de9/health.json
- [Zero catalog index](https://www.zero.xyz/llms.txt)
- [Other services from x402-zoo.lolagent.workers.dev](https://www.zero.xyz/host/x402-zoo.lolagent.workers.dev/llms.txt)